John mcmurtry



UNITED STATES PATENT OFFICE.

JOHN MCMURTRY, OF LEXINGTON, KENTUCKY, ASSIGNOR TO DANIEL VIEHL.

MODE OF CONTROLLING COG-GEAR SASH-BALANCES.

Specification of Letters Patent No. 18,223, dated September 15, 1857.

To all whom it 'may concern:

Be it known that I, JOHN MCMURTRY, of Lexington, in the county of Fayette and State of Kentucky, have invented a new and useful Improvement in Controlling and Opv erating that Description of Sash which is at Present Balanced by Cog-Gearing; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming part of this specification, in which- Figure l is an end or edge view of the window frame. Fig. 2 is a vertical transverse section of the same in the line of Fig. l.

Similar letters of reference in each of the several figures indicate corresponding parts.

The nat-ure of my invention consists in arranging the cog gears of the lower sash on a shaft which is capable of turning vertically, and sliding horizontally, and which has arranged on its end a locking plate which slides with it, but which cannot turn with it, said plate having a bur or cog on its edge which serves as a stop to hold both or either of the sashes in any desired position when geared together or separated.

By my arrangement both of the sashes can be operated and locked elevated by the same device, or by simply operating one shaft, thus the necessity of having a separate catch or lock which is always getting out of order is avoided.

My arrangement also provides for the independent operation of the lower sash and the operation of both in such a manner as to render possible, what heretofore has been impossible with the cog gear sash balance, the having of the upper sash open while the lower is closed or vice versa. This advantage, with the facilities kfor locking in any position by simply the sliding of the same shaft which operates the shaft by being turned, is of the utmost importance in connection with the cog gear balance, and will render its introduction into public use very extensive as it can be applied to old houses, which cannot readily be done, at small cost, if the cord, pulley and weight balances must be used, which are at present preferable to the old style of cog gear balance, on account of the weights holding the sash at any elevation desired, which is not the case with any other styles of cog-gear balance besides mine, which, besides possessing this advantage admits of either one or both sashes being operated at a time.

To enable others skilled in the art to make and use my invention I will proceed to describe its construction and operation.

A represents the window frame made of usual construction with the exception of a recess being cut through the side jamba, as shown at B. C, C', are t-he sashes also made as usual, with the exception of a recess being cut in the edge of each to receive a toothed rack.

D, D', are the toothed racks which are fitted firmly in the edge of the sashes.

E, is a metal plate fitted in the recess B, so as to stand Hush with the insideof the jamb. This plate has a bearing or support Y), c, projecting from its back on which the shafts of the cog gears which operate the sashes rest.

F, F', are the cog gears which operate the sashes, are arranged first on shafts G, G',

=`and their teeth pass through slots 0l, al, in

the plate E, and gear with therack s as shown in Fig. 2. These gears are combined by means of intermediate pinions H, I-I', one on the shaft G, and the other on the shaft G', and both turning with the same.

I, is a stop plate arranged loose circumferentially, but fast, longitudinally, on the shaft G'. This plate has one portion of its edge flat so as to bear against the back of the plate E, and thus be held from turning while the shaft is turned. It also has a bur or cog f on its edge so that it shall serve as a lock to hold the sash or sashes in any position desired.

J, is a knob on the front end of the shaft G, by this knob the shaft is both turned and slid.

Operation: To open both sashes the gears of the lower sash would be in the position shown in red; when in this posit-ion by simply turning the knob the upper sash will be caused to descend while the lower one ascends. This being done, the gears of the lower sash should be drawn to the position shown in black. This will throw the bur or cog of the plate between the teeth of the upper pinion, and thus lock the sashes securely. Now to operate the lower sash separately it is simply necessary to have the parts in the position shown in black, and then to turn the knob, as the stop plate remains stationary while the shaft G', turns. If it is desired to only have the upper sash ion open or down a short distance, all that is necessary is tov operate the two together the required distance, then ungear the two sashes, vrun the lower'one down and draw the shaft G out until the buror cog of the stop plate occupies a place between the teeth of the upper pinions and prevents the same turning.

What I clairnas my invention and desire to secure by Letters Patent, is-

Arranging the cog gears E H of the lower sash C on a shaft G', which is capable of turning vertically and sliding horizontally, and which has arranged on its back end, a locking plate I, which slides with it; but which cannot turn with it, said plate having a bur or cog f, on its edge which serves as a stop to hold both or either of the sashes in any desired position when geared together or separated, substantially as and for the purposes set forth.

JNO. MCMURTRY.

Vitnesses:

GEORGE STOTT, JAoKsoN M. TAYLOR. 

